1989: Dive depth: 33 ± 1 m, max= 42 m (N=26 birds)
1989:
(maximum depth gauge, 150mm long, 1.7g)
1989:
Dive depth: 35.5 ± 0.9 m, max= 43 m (N=13 birds)
1989:
(time-at-depth gauge, 90x11 mm, 11g)
REF 1
1987-89: Dive duration: 62 ± 1.92 sec, max= 163 sec (N=31 birds)
1987-89:
(radio-transmitter, 19g, 42x15 mm + 325 mm aerial)
REF 2
1989: Dive depth: avg= 30.1 ± 2 m, max= 43 m (N=13 birds)
1990: Dive depth: avg= 19.7 ± 4.6 m, max= 45 m (N=14 birds)
1990:
(Photographic time-at-depth recorder, 11g, 90x11mm)
REF 3
1996: Dive depth: 20.5 ± 1.3 m, max= 34.6 m (N=21 birds)
1996:
(Mk5 Wildlife Computers, 50 g, 60x35x15mm; 1m accuracy, sampling: 1s)
REF 4
1997: Dive duration: avg= 63.3 ± 2.7 s (N= 40 birds)
1998:
(radio-transmitter)
1998: Dive depth: avg= 27.2 ± 2.6 m (N= 19 birds)
1998:
Dive duration: avg= 71.9 ± 2.9 s (N= 19 birds)
1998:
(radio-transmitter + time-at-depth gauges)
2001: Dive depth: avg= 22.8 ± 1.1 m (N= 29 birds)
2001:
Dive duration: avg= 62.4 ± 2.1 s (N= 29 birds)
2002: Dive depth: avg= 20.6 ± 0.8 m (N= 48 birds)
2002:
Dive duration: avg= 58.2 ± 1.3 s (N= 48 birds)
2003: Dive depth: avg= 26.7 ± 2.2 m (N= 8 birds)
2003:
Dive duration: avg= 68.8 ± 3.5 s (N= 8 birds)
2003:
(PreciTD temperature depth loggers, sampling= 2 s)
REF 5
1990: Dive depth: avg= 32.2 ± 13.4 m, max= 61 m (N=6 birds)
1990:
(Photographic time-at-depth recorder, 11g, 90x11mm)
REF 3
1976-82: Dive duration: avg= 38.4 ± 7.8 s, max= 50.8 s (N=50 dives)
1976-82:
(Observation from land by binoculars + stopwatch)
REF 7
1994-95: Dive duration: avg= 38 ± 2.23 s (N=5 birds)
1994-95:
(TW3 VHF transmitters, Biotrack, 18g, 30x20mm + 2 aerials 280 & 230mm)
REF 8
1989: Dive depth: avg= 28.1 ± 6.3m, max= 39.6 m (N=12 birds)
1989:
(Capillary depth gauges, MicroLine, 1.02mm in diameter)
REF 9